Location: Tvarditsa - one of the villages in the municipality of Burgas in the south-eastern Bulgaria. Burgas, including southern Bulgarian Black Sea coast, bordered to the south by Turkey. The municipality is named after its administrative and industrial center - the city of Bourgas - the fourth largest city in the country. That sea creates the appearance of Bourgas and the unique atmosphere engendered by centuries of contact with different peoples and civilizations. The city is surrounded by lakes, and located in the most western point of the Black Sea, on a huge Bourgas Bay. Burgas is a commercial and tourist center. Mandra Mandra lake or lake - the most southern of the Bourgas lakes located in close proximity to the Black Sea and just a kilometer from the village of Tvarditsa. Length of 8 km and a maximum width of 1. 3 km, an area of